Summary of the Turbulence Incident & TSIB Report
this report details a turbulence incident occurring on a flight descending through 18,700 feet near Sanya, China on an unspecified date (report released Oct 18th, 2025). The turbulence resulted in injuries to 11 people – 1 passenger with serious injuries requiring hospitalization, 3 passengers and 9 cabin crew with minor injuries. The aircraft landed safely with a 2-hour delay.
Key Findings of the TSIB examination:
* Cause: The primary cause was unexpected turbulence encountered during descent, likely linked to a convective cell that developed rapidly to the south of the aircraft.
* Limited Detection: The convective cell was not visible on the aircraft’s Weather Radar (WXR) because it was behind the aircraft and developed quickly. The radar also doesn’t always detect all turbulent air pockets.
* Fasten Seatbelt Sign Decision: The Pilot-in-Command (PIC) reasonably kept the fasten seatbelt signs off as there was no observed adverse weather ahead and the descent hadn’t reached the 10,000ft altitude where the signs are required.
* Not Related to Typhoon Yagi: The investigation ruled out Typhoon Yagi as a contributing factor, as it was too distant from the incident location.
Vital Reminders & Lessons Learned:
* Caution Near Convection: flight crews should exercise caution when operating near any convective activity.
* Seatbelt Use: passengers should always keep their seatbelts fastened while seated, even during seemingly smooth flight.
* WXR Limitations: Aircraft WXR is not foolproof. It functions differently than ground-based radar and may not detect all turbulence, especially rapidly developing or rear-located convective cells. Green returns on WXR don’t guarantee safe passage.
* Weather System Range: An aircraft can be affected by a weather system even after flying past it.
In essence, the report highlights the unpredictable nature of turbulence and the importance of proactive safety measures – both by the flight crew and passengers – even in the absence of immediately visible threats.
